Antimicrobial agents are commonly used in the treatment of skin abnormalities or disorders that can lead to acute or chronic symptoms such as redness, acne, inflammation, rash, burning, stinging, itching, flaking/scaling skin, malodor, and the like. The antimicrobial agent can provide a dermatological, and/or therapeutic effect in the treatment of the skin abnormalities or disorders. Therefore, antimicrobial agents are also commonly referred to as “antimicrobes”, “active agents”, “antibacterial agents”, “bacteriocides”, “enzyme inhibitors”, “anti-acne agents”, “antifingal agents”, “antiviral agents”, and so forth.
The type of antimicrobial agent used to treat the skin disorder will generally depend upon the acute or chronic symptom. For example, lipase and/or protease inhibitors are typically used to treat diaper rash, salicylic acid and N-acetyl-L-cysteine compounds are typically used to treat acne, and hexamidine and pentamidine compounds are typically used to prevent the formation and growth of bacteria and fingi. These antimicrobial agents can be used alone or in combination with other antimicrobes at reported individual concentrations of at least about 1% to provide a skin treatment benefit.
One reported attempt of using an antimicrobial agent such as hexamidine to treat fecal proteases is disclosed in WO 99/45974. This reference discloses the application of a protease inhibitor such as hexamidine onto an absorbent article for ultimate delivery of the hexamidine onto the skin, resulting in the transfer of a protease inhibitor having defined assay parameters such as an IC50 of 30 μM or less. The hexamidine protease inhibitor, particularly hexamidine diisethionate, described in the WO 99/45974 reference is typically employed at concentrations of about 1% or greater.
Another reported attempt of using one or more antimicrobial agents to prevent or treat skin disorders such as diaper dermatitis is disclosed in WO/45973. WO/45973 discloses skin care compositions comprising compounds such as hexamidine and its salts that can be included in the skin care compositions with other known skin active agents such as panthenol, and zinc oxide applied to absorbent articles. The WO/45973 reference also discloses the employment of hexamidine antimicrobial agents at effective concentrations of about 10%.
It has been found, however, that hexamidine can be included in skin care compositions at low concentrations (about 0.1% or less) to provide effective skin treatment benefits such as the prevention and reduction of erythema, malodor, and other bacterial skin disorders when used in combination with a low concentration of other skin active agents such as zinc oxide and/or niacinamide.